Thermopiles



March 1 6, 41954 l.. suKAcEv THERMOP ILES Filed Marchl 9, 1950 vFicih A noentor.'

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Gtforneg Patented Mar. y16, 1954 UNITED Stmas PATllilllA ammala TH'RMOPS" Lev Sulfacev; Chevy ovliasei'lii'd.' iispiitiiioi 9, i956', saai ha idilio- (cl. las-41) inte-'rm latel junctions" aref grouped on substantially opposite s de of thel'ielix.L

Relatively simple" andY inexpensive methods arev employed in ...consiruiieg this. ihermopile'.; A

leiiieiiiiiiig fieiniiii @nasi ihecsie is thidthj. Thusyirisf'sithati iheihiopi'i is fornidhaviiigrthe herein-described structure.

1 is a side View of a thermopile according lo ih'e'ioveniiori; Fig `2- ifs an enlarged sectional'view on line 2"2 Oflefll Y.

flair .is an enlarefifi-yetial gsetienr-al en longitudinally 4of a fragment of the thermopile shown in Fig. 1;

Figsrlf; 5 and 6 are diagrammatic viewssll'owin'gE respectively a vertica'l'longitdinalf'Y section, a vertical lateral section, and a plan-view of anparatus"to illustrate steps inanethodif lriiaking the thermopile.

In constructing a thermopile of the present invention, a rod of dielectric material i I" any desired length and Cross-section is provided with a thin conductor coating 2 of relatively high electrical resistance as compared with the metals employed in the thermopile. By employing the thus coated rod as an electrode, one side is electroplated with one of the metals 3, such as copper, to serve in the thermopile. The opposite side is electroplated with a different metal 4, such as nickel. The edges of the metal layers 3 and 4 overlap as at 5 and 6 on substantially diame+ ricaily opposite sides of the rod I.

After the metal layers 3 and 4 are provided, the coated rod is revolved on its longitudinal axis se a'rate'd by a" spa out T. A terminal may 'e of the l'ielcalthriob e as lThe regi* f snowf though' this may' b 'rg' elliptical,y or any desired andvsiitavb'l sliap l. In eacl' case the pile formedA isL qosizieiea' siihsiaiiallyile'licall ii 'its' configuration; TheJ mui 1 may alslhe tubular; if desired, aha" provid lfw'iih closed ens. g

The' material sith di ljc'iii in ihe'rodjl may be any suitable" in ulatig' substance. Plastics are'pre'ferred andtlse'maf i'ncludealjly of vari'- ous types' suoli as' pheiiligcell'ulose; acrylic,

vinyl; urea formaldehyde or other' resins. They' may her thermoplastic thrihosettihgf depend'- ing on the Conditions under' which the thermopile is to' beeihployed; w l l l In nialiingahrmobil by nelectroplating process, for exainpiyardf'm pf'iilectric'matfrial isp'lfovidedvvith mel 'whereby it may s've asf'a cathode? Forthis' pilriosjapair of angular metal supporting means is screwed into thei'side' ofrod'ilyatfeach 'eiidtas at 15,16; I7, and: is, The'meta'l'suhortlngmeans iii'each ehde'xtend in"opposite".direeiionsfrhih the' side ofthe rod. The 'r'o'With tfs' atta'chmentsis then provided witli'a'conductor coating'` of" relatively high r'esstance'; Anamely; 'in theffollowirig manner:

Thef'rod'is cleanedwithfalcohol and submergedV iria` 5 'per cehtsoluiiorffofftin chloride for 15 minutes.` The rod is 'removed and washed," and Coated `Witl1"a"'1ln"1"of 1vsilvei" of such-thinne'ss" 'that its resistance is relatively liigh. This 's'do'n by placing'the rod :in a' batlfprepared' from' Z'O'p'arts of a solution A and l part of a solution B, the folmula of each solution being that indicated be 0W.

The rod is removed from the silvering bath after about 15 minutes and is washed and dried.

3 It is now ready for electroplating. It is noted that the silver film covers the entire surface of the rod and makes electrical contact with the meta1 supporting means I5, I6, I1 and I8.

Instead of silver, it is possible to attach a thin continuous layer of carbon particles to the surface of the rod, and then to subject the coated rod to the electroplating processl described below.

For purposes of exemplication, the electroplating apparatus shown in Figs. 3, 4 and 5, comprises a tank containing electrolyte 2|. 22 represents an anode of the metal to be deposited on the rod E4. The anode 22 is electrically connected to and suspended from conductors 23 and 24. The silvered rod I4, serving as a cathode, is suspended in the electrolyte by means of conductor elements 25 and 26 upon which the ends of the metal supporting means I5 and I1 rest. Proper connections are made to complete an electric circuit through the electrolyte.

To coat one side of the rod I4 with copper, for instance, the rod is positioned in a copper bath, as shown in Fig. 3, and the level of the bath is maintained so that the rod is submerged to a depth slightly greater than its radius. After the copper is deposited to a thickness substantially greater than the thickness of the silver nlm, the rod is removed from the copper bath, Washed, dried, and the other side of the rod is coated with nickel, for instance, by placing it in a nickel bath and Vsupporting it Yby the means I6 and I8 in a manner similar to that in which it is supported in the copper bath. As in the case of the copper bath, the level of the nickel bath is maintained so that the rod is submerged to a slightly greater depth than its radius to insure overlapping of the deposited metal layers, as shown in Figs. 1 and 2.

After the copper and nickel layers are deposited on the rod I4, in the manner described, one of the metal supporting means I6 and I at either end is removed and the angle end of the metal supporting means I5 and I8 is cut ofl to form the terminals similar to the terminals I0 and il in Fig. 1. By the electroplating process described, good electrical contact is made between the deposited metal layers and these terminals.

Electroplating is preferred, but an alternative method of applying the metals of the thermopile to a core, comprises shielding substantially one longitudinal half of the core while exposing the other half to a metal vapor to obtain a coating, then shielding the resulting metal coating with the exception of a strip along each edge of said coating, and exposing the remainder of the surface to vapor of a diierent metal until a coating of the latter metal is formed which overlaps the said rst metal in said strips.

The helical cut is next made in the side of the rod through the coatings and into the dielectric material underneath. A ribbon of any desired Width may thus be obtained with terminals at either end. The thermocouples in the pile are in alignment on opposite sides of the helix. The dielectric material serves to mount the metals of the pile on a solid base of any desired length usable as a thermopile unit and for easy installation. A simple, efficient pile is readily constructed and adapted to various uses. Its electromotive force may be easily varied with the length of the helix, by the number of turns in the helical ribbon, by the metals used, by coupling any number of these piles, and by other means.

The invention as hereinabove set forth is embodied in particular forms and manner but may be variously embodied within the scope of the claims hereinafter made.

I claim:

1. In a thermopile comprising a helix of metallic ribbon having alternate sections of one metal and intermediate sections of a diierent metal, said sections supported on the outer surface of a core of plastic dielectric material and joined end to end in overlapping relationship forming a plurality of thermocouples; a helical kerf provided through the metal and into the core for forming the edges of the said ribbon and spacing the successive circumvolutions of said ribbon from each other in raised position on the surface of the said core.

2. In a thermopile comprising a helix of metallic ribbon having alternate sections of one metal and intermediate sections of a different metal, said sections supported on the outer surface of a core and joined end to end in overlapping relationship forming a plurality of thermocouples; a. helical kerf provided through the metal and into the core for forming the edges of the said ribbon and spacing the successive circumvolutions of said ribbon from each other in raised position on the surface of the said core, and the said core comprising thermoplastic dielectric material.

. LEV SUKACEV.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,585,159 Logwood May 18, 1926 1,667,142 Darrah Apr. 24, 1928 2,023,264 Brucker Dec. 3, 1935 2,137,309 Smulski Nov. 23, 1938 FOREIGN PATENTS Number Country Date 24,968 Great Britain Nov. 17, 1900 of 1899 34,505 France Feb. 5, 1929 

